Project 7 is part of a continuing effort to extend the limits of behavioral methodology for teaching people with severe, lifelong learning difficulties. The study population is children and adults with mental retardation whose future is likely to include community placement but whose language skills render them difficult or impossible to teach with usual methods of instruction. Project 7 addresses questions about the ecological validity of the largely process-oriented research conducted previously by our research group and proposed elsewhere in this PO1 application (see Projects 1-4). We examine the applicability of our laboratory findings to computer-based activities that establish functional sight-word skills. We have developed several advanced teaching methods for establishing new stimulus-stimulus and stimulus-response relations in standard and constructed-response matching to sample. Those relations engender networks of matching, naming and writing performances. Previous studies by our research group and others have shown that these techniques may be useful not only for studying basic learning processes but also for teaching prerequisites for functional communication skills. The studies show further that these techniques may increase teaching efficiency because they lead to the emergence of new behavior that has not been directly conditioned. Prior to our first PO1 project, however, no one had established the foundation for the next logical step, integrating the techniques into a broad methodology for establishing repertoires of stable, flexible, adaptive behavior. Project 7 seeks to develop such an integrated program for teaching the functional use of sight words. There are at least three levels of intervention-oriented research that may be identified with respect to the development of sight-word instructional programs: (a) research that asks whether a particular procedure or program is effective; (b) comparative research that assesses the relative efficacy of two or more procedures or programs; (c) research that examines generalization and transfer from training settings to functional activities. The studies proposed in Project 7 address questions about intervention effectiveness, relative efficacy, and generalization. The Specific Aims of Project 7 are: (1) to determine whether exclusion-based methods will be generally effective to teach auditory-receptive reading performances; (2) to assess the effectiveness of recently developed sample stimulus-shaping methods to teach sight-word comprehension; (3) to extend analyses of two procedures, stimulus fading and delayed matching with complex samples, for teaching spelling in the context of computerized constructed-response matching to sample; (4) to compare the efficacy of the exclusion and stimulus-fading methods to standard methods of instruction (time-delay procedures); (5) to determine the extent to which sight-word skills acquired by computer-based instruction are functional outside the training context, by examining generalization to (a) traditional "tabletop" teaching situations, and (b) instruction-following tasks. If generalization is incomplete, we will explore methods to program transfer of training; and (6) to develop a program for expanding the network of stimulus equivalence relations from a basic sight-word vocabulary to an extended repertoire of matching, reading, and spelling skills that are functional in everyday instruction- following activities.